The fight between Oberyn (Pedro Pascal) and The Mountain (Hafthor Julius Bjornsson) is all the rage online — and Graves has plenty to say about the gritty details of getting that gruesome scene right. (See below.)

But he says one of the episode's quieter scenes will have huge ramifications for season five. It's the moment in which Ramsay Snow (Iwan Rheon) becomes Ramsay Bolton.

"The Boltons have taken the North and they are now powerful. The man who helped carry out the Red Wedding has capitalized on his success in a very significant way," Graves tells The Hollywood Reporter. "Ramsay and Roose — one of the things that really sets the tone for next year is they've really got some serious power going now."

Pretty much every storyline had a major turning point last night. Which was the most challenging to get right?

The moment I was most worried about in that hour was Dany and Jorah. I knew about that moment since I started the show. When you get into a scene with Emilia Clarke and Iain Glen, you get twice as worried that you make it in a way that they will be happy [with], because you just fall in love with them. I was stressed out, wanting to take it to a level of tension that was unusual, and hopefully we got it there.

It's heartbreaking to see Jorah have to go away.

People [book readers] know that scene, but I wanted to make the acting so incredible that it felt like they didn't know that scene. I think the actors really delivered on that. We did about 10 takes of each of them. We spent a fair amount of time growing it. For all the talk of the fight, I hope people look back and [see the] incredibly complex narrative turn in Emilia Clarke's performance last night. I think she was brilliant.

I looked at it as the story of the fight. "At this point in the fight we don't think this, but we think this." Then they would rehearse it with the stunt fighters, and I would go in and edit it, and we'd put the actors in. We discovered tings like wanting to get the Mountain's helmet off early so you could see his face — we were crazy about Hafthor. He's so great and I love him.

And these two characters' very different fighting styles, what were you going for there?

We wanted it to be very heavy and centered with The Mountain and incredibly fluid and slick around Oberyn. You've been hearing throughout the season that Oberyn is a good fighter. So the first thing you've got to establish — especially if he's fighting The Mountain, who has killed anyone he's ever fought — is "Oh, I've never seen anything like this guy on the show." On Game of Thrones it's usually "Draw my sword, cut him in half, blood, guts and its over." This was artistry — with poison.

You've got to build that suspense. I want people to think, "Oh, how is Tyrion going to get out of this thing? This must be it, right? They're not going to kill Dinklage, right?"

How'd you get the gruesome effects down for Oberyn's death?

I storyboarded it for, "This is when we're going to use Pedro, and this is when we're going to need some kind of a head that can implode." I sent our makeup supervisor off and he built this head to use for the shots. Then the visual effects guys took it home by putting a little swelling in the head, and making the one eye look really bad. The last composition that we barely got before the sun went down was of the two of them lying dead – the effects team made that even more gruesome. They rearranged some of his brain matter.

Sophie Turner as Sansa had another great performance here. What was the key to that?

I talked with Sophie and said, "The whole scene depends on the fact that when you tell the lie and have your breakdown, no one will have any idea that you are lying. You're not acting. You've got to do it and be in it like it's a sincere dramatic scene." She just knocked it out of the park, and what you see in that last third when she starts to break down is one take. I was so proud of her. That's a big thing for an actress that young.

She has made the ultimate, fairly brilliant political move of siding with the one person who gives her the best chance of surviving against the Lannisters, who want her dead. She's got to make the most powerful alliance she can. Who is the smartest person in the room? That's Littlefinger.

What did you talk to Aidan Gillen (Littlefinger) about for the interrogation scene?

I went to [showrunners] David [Benioff] and Dan [Weiss] after I got the script and said, "I'd like to film Aidan's face for the first minute of the scene and never cut." That scene was about two people who were really, really lying, and you cannot tell because they are so good at it. The only direction I really had to give to Aidan was, "I'm going to start the scene on your face six inches from your nose." That's where the tension is. He looks like he's thinking, "How do I get out of this one?"

Tyrion is absolutely captivating in his cell scene, even though it's the rare Thrones scene that doesn’t really move the plot forward. How's that work so well?

It's really about the futility of where Tyrion is as he's waiting for the trial by combat. We went in to rehearse, and Peter [Dinkage] and Nikolaj [Coster-Waldau] did the scene, and it was unbelievable. I didn't prepare, Peter did. And Nikolaj did. I literally turned to David and Dan after rehearsal and said, "That's one of the most brilliant scenes I've seen on the show." I hadn't digested how incredible it would be until Peter did it. It's like you read sheet music, and then Yo-Yo Ma plays it.

Theon just gets better and better this season. What were his scenes all about for you?

Alfie [Allen] is such a great actor, and he's so good as Theon. It was fun to see him have to go into public as Reek and pretend to be himself. And for Moat Cailin, we were totally out of money. Moat Cailin was like a joke on the show — we called it "No Cailin" because there was no money to do anything.

It's a typical Ramsay move, but it's in fact setting up next season. The Boltons have taken the North and they are now powerful. The man who helped carry out the Red Wedding has capitalized on his success in a very significant way. Ramsay and Roose — one of the things that really sets the tone for next year is they've really got some serious power going now.

It's hard not to be a little touched for Ramsay when he becomes a Bolton — but then we remember he's a total monster.

The core of his whole psychology is he has been completely rejected and belittled by his father since the beginning. He's so floored by what's happening that you really feel emotion for the guy. If you can just imagine Roose being your father, you wouldn't have a cell of self-esteem left.

We can't wait to see the finale, which you are directing.

No comment. If you liked last night, you'll like it. And next week is going to be incredible too.